Various types of control valves are known in the art. The following publications disclose some examples. U.S. Pat. No. 5,139,225 discloses a pneumatically controlled valve system featuring simplified modular construction, reduction of moving parts, improved control of valve operation and increased resistance to corrosive effects of transfer fluid used with the valve. The operation of the valve is pneumatically controlled through specially designed, removably attached gas inlet and outlet ports with orifices of pre-selected lengths and internal diameters designed to affect the introduction rate of the pressurizing gas, which drives the valve stem assembly by the deflection of the upper and lower diaphragms of the valve stem assembly, thus reducing shock to the valve system by rapid valve closure and possible damage to valve components.
U.S. Pat. No. 6,354,813 discloses a three-way-valve actuated by fluid which moves membranes.
Another example is disclosed in U.S. Pat. No. 8,141,585 directed to a rocker type diaphragm valve. The diaphragm in the diaphragm valve is asymmetric and the stroke of the diaphragm is offset from the center of the diaphragm. The two sealing surfaces that the diaphragm acts against form two planes that make an angle with respect to one another. The diaphragm may be fabricated in only one piece. The diaphragm may also be made from a resilient material and shaped in such a way as to create a spring force holding the diaphragm into a default position in the valve.